Family law attorney practicing in Texas for 14 years. Postnuptial agreements after infidelity are one of the most common requests I receive, and they can be effective tools for rebuilding trust -- but they must be drafted carefully to be enforceable.
In Texas, postnuptial agreements are governed by the Texas Family Code Section 4.105, and the enforceability standards are actually stricter than for prenups. Key requirements include:
- Both parties must have independent legal counsel (not the same attorney)
- Full financial disclosure by both parties -- any hidden assets can void the entire agreement
- The agreement cannot be unconscionable at the time of enforcement
- It must be signed voluntarily without coercion or duress
- There must be adequate consideration (the continuation of the marriage is generally sufficient)
Regarding the infidelity component specifically: Texas is one of the states where fault can be considered in property division during divorce. Under Family Code Section 7.001, a court can consider adultery when making a just and right division of community property. A well-drafted postnup can establish specific consequences for future infidelity, such as a predetermined property split favoring the faithful spouse.
However, I want to flag a common pitfall: infidelity clauses that are punitive rather than compensatory may be challenged as unenforceable. Courts have struck down provisions that would leave the cheating spouse with nothing, viewing them as penalties rather than fair adjustments. A better approach is to establish a specific percentage split (such as 60/40 or 65/35) rather than an all-or-nothing clause.
From a practical standpoint, I always recommend that the postnup also address the emotional side of things -- require couples counseling, establish transparency expectations for finances and communications, and include a review clause where both parties revisit the agreement after 2-3 years. This signals to a court that the agreement was part of a genuine effort to repair the marriage, not a coerced punishment.